Boil the beans for forty minutes if they are fresh or for 2 hours if
they are dried and have previously been soaked for half an hour. For the
correct procedure for cooking beans, please see the relative recipe.
Cut the onion up finely and add to the tuna fish (that you will have
flaked) in a bowl. Add the cold, well-drained beans. Season with olive
oil, salt and freshly-ground pepper.